Анотация: Abstract. Analysis of the need to consider the fractional composition of coal dust in the calculation of the
dust load is carried out. The impact of cycles of freezing and thawing on the fractional composition of the dust
generated during mechanical destruction of coal marks D are found. To achieve this goal, in vitro experiments
were carried out with coal mark D of the Tugnuisky deposit. The collected sample was split into smaller samples
and, with the help of mechanical crushing followed by classifying, the following fractions were obtained: 1 mm,
1 + 0.63 mm, 0.4 mm -0.63, -0.4 +0 25 mm, -0.25 mm + 0.2, 0.2 + 0.14 mm, -0.14 mm. For determining the
fractional composition of the coal, depending on the degree of hydration was used Camsizer XT installation, which
allows obtaining a density distribution of particles in a sample. Altogether were conducted 80 trials, of which 40 -
in the natural moisture and 40 - with artificial moisture (full saturation).
The experimental results showed that there is a relationship between the fractional composition of the sample,
its moisture content and the number of cycles of freezing and thawing. It is shown that the level of dust, depending
on the number of cycles at increasing humidity is substantially reduced: by the degree of destruction of 7-fold
effect of the dry coal is 1-fold to humidified coal.
Also was found the effect size fractions on the degree of destruction. In particular, the processing of the
experimental data showed that the initial fraction of less than 0.14 mm output of fine dust does not change, and
further research may be excluded from the analysis. The maximum degree of destruction observed dust sample
fractions 1 + 0.63 mm, which should be used in determining the impact of man-made laws of moisture on the
fractional composition of the dust in the cyclic cryogenic effects. The established regularities will continue to
develop the best plan of experimental work to achieve this goal for different marks of coal.